1. Field of the Invention
The present invention relates to an electrotherapeutic device for passing a DC electric current through a living organism, and, in particular, to an easily handled electrotherapeutic device which produces no excessive flow of current even if the resistance of the living organism fluctuates.
2. Description of the Background Art
Many and various types of electrotherapeutic devices for passing electric current through a living organism are commonly known, mainly for use in medical treatment. They are broadly grouped into those for obtaining therapeutic effects from the passage of the electricity itself, which are used for the needle treatment and the like, and those for obtaining a therapeutic effect by injecting a drug into the living organism by means of the passage of electricity; a therapeutic method called iontophoresis.
Iontophoresis is a technology by which drugs are administered electrically for intracutaneous absorption. Iontophoresis have conventionally been considered to be effected by the mechanism in which the drugs are first ionized by the application of electricity, then absorbed intracutaneously. There are, however, the cases in which drugs are absorbed without prior ionization, and in which drugs are absorbed from both positive and negative electrodes. Many points remain to be theoretically elucidated about the mechanism of iontophoresis.
Intracutaneous electrical devices present some problems such as side effects which accompany the application of electricity, including shock, pain, burns, and the like. It is believed that these side effects occur because the resistance of the skin and the like fluctuates when electricity is passed through an organism so that the flow of current is greater than required, and also because the current density becomes localized from inadequate adhesion of the electrode pad to the skin.
A method conventionally adopted as a countermeasure to the above problem areas is providing a current regulating means such as an external resistance, a switch, or the like.
However, in all these countermeasures the current regulating means are separately provided outside of the power supply source for controlling the electric current. The device therefore becomes large and difficult to handle. An additional problem is nuisance involved in manipulating the current control device. For these reasons, it is difficult for the patient himself to use such a device, making it necessary for him to go to a hospital for treatment by a doctor.
Accordingly, the development of an electrotherapeutic device for passing an electric current through a living body which is safe, with no excess current flow, easy to handle, and also inexpensive has been eagerly awaited.